The present invention relates generally to electrical medical leads, and more particularly to stimulation leads of the type which dispense a steroid or other drug adjacent to the stimulation site. The invention is particularly useful in the context of a cardiac pacing lead.
Delivery of a drug at the stimulation site of an implantable pacing lead is disclosed in U.S. Pat. No. 4,711,251, issued to Stokes. A particularly desirable configuration for such a lead is disclosed in U.S. Pat. No. 4,506,680, also issued to Stokes. In this configuration, the drug to be dispensed, a glucocorticosteroid, is compounded with silicone rubber based medical adhesive, and located within a chamber within the distal end of the stimulation electrode. The steroid acts as an antiinflammatory agent, reducing the effects of inflammation due to the reaction of the tissue to the stimulation electrode.
Alternative embodiments of stimulation electrodes which elute a steroid or other drugs are disclosed in U.S. Pat. No. 4,606,118 issued to Cannon et al and in U.S. Pat. No. 4,577,642 issued to Stokes. A myocardial pacing lead adapted to deliver steroid at the stimulation site is disclosed in Statutory Invention Registration No. H356, by Stokes et al in which a steroid is delivered through a barbed electrode to a delivery point within the myocardium.